Vaccine development in horses involves the creation and refinement of immunizations to protect equine populations from infectious diseases. This process includes identifying antigens, formulating vaccines, and evaluating their safety and efficacy through clinical trials. Vaccines stimulate the horse's immune system to recognize and combat specific pathogens, thereby reducing the incidence and severity of diseases. Common equine vaccines target diseases such as equine influenza, tetanus, and West Nile virus. This page compiles peer-reviewed research studies and scholarly articles that explore the methodologies, challenges, and advancements in vaccine development for equine health.
Diaz-San Segundo F, Dias CC, Moraes MP, Weiss M, Perez-Martin E, Owens G, Custer M, Kamrud K, de los Santos T, Grubman MJ.We have previously shown that delivery of the porcine type I interferon gene (poIFN-α/β) with a replication-defective human adenovirus vector (adenovirus 5 [Ad5]) can sterilely protect swine challenged with foot-and-mouth disease virus (FMDV) 1 day later. However, the need of relatively high doses of Ad5 limits the applicability of such a control strategy in the livestock industry. Venezuelan equine encephalitis virus (VEE) empty replicon particles (VRPs) can induce rapid protection of mice against either homologous or, in some cases, heterologous virus challenge. As an alternative approach ...
Glass K, Barnes B.When novel disease outbreaks occur in livestock, policy makers must respond promptly to eliminate disease, and are typically called on to make control decisions before detailed analysis of disease parameters can be undertaken. We present a flexible metapopulation model of disease spread that incorporates variation in livestock density and includes occasional high-mixing locations or events, such as markets or race meetings. Using probability generating functions derived from this branching process model, we compare the likely success of reactive control strategies in eliminating disease spread...
van Kasteren PB, Bailey-Elkin BA, James TW, Ninaber DK, Beugeling C, Khajehpour M, Snijder EJ, Mark BL, Kikkert M.Protein ubiquitination regulates important innate immune responses. The discovery of viruses encoding deubiquitinating enzymes (DUBs) suggests they remove ubiquitin to evade ubiquitin-dependent antiviral responses; however, this has never been conclusively demonstrated in virus-infected cells. Arteriviruses are economically important positive-stranded RNA viruses that encode an ovarian tumor (OTU) domain DUB known as papain-like protease 2 (PLP2). This enzyme is essential for arterivirus replication by cleaving a site within the viral replicase polyproteins and also removes ubiquitin from cell...
Andoh K, Takasugi M, Mahmoud HY, Hattori S, Terada Y, Noguchi K, Shimoda H, Bannai H, Tsujimura K, Matsumura T, Kondo T, Maeda K.A major immunogenic region of equine herpesvirus (EHV)-1 glycoprotein E (gE) was identified. Firstly, the various fragments of EHV-1 gE were expressed as fusion proteins with glutathione S-transferase (GST) in Escherichia coli and their antigenicities were compared by immunoblot analysis using sera from horses experimentally infected with EHV-1. Thirty-three amino acids of gE (a.a. 169-201) specifically and sensitively reacted with the antibodies induced by EHV-1 but not EHV-4 infection. The corresponding region of EHV-4 gE (a.a. 169-199) did not react with antibodies to EHV-1, indicating that...
Rossi SL, Guerbois M, Gorchakov R, Plante KS, Forrester NL, Weaver SC.Venezuelan equine encephalitis virus (VEEV) is an arbovirus that causes periodic outbreaks that impact equine and human populations in the Americas. One of the VEEV subtypes located in Mexico and Central America (IE) has recently been recognized as an important cause of equine disease and death, and human exposure also appears to be widespread. Here, we describe the use of an Internal Ribosome Entry Site (IRES) from encephalomyocarditis virus to stably attenuate VEEV, creating a vaccine candidate independent of unstable point mutations. Mice infected with this virus produced antibodies and wer...
Diouf ND, Etter E, Lo MM, Lo M, Akakpo AJ.Since first being detected in Nigeria in January 2007, African horse sickness virus serotype 2 (AHSV-2) has spread throughout the northern hemisphere, and was first reported in Senegal. A retrospective study was conducted from December 2009 to April 2010 using data collected in the field combined with information available at the Direction of Veterinary Services. The epidemic started in the Dakar region with two outbreaks in March and June 2007, respectively, and spread in several parts of the country between July and November 2007. During this period, 232 outbreaks and 1137 horse deaths were ...
Soares SC, Trost E, Ramos RT, Carneiro AR, Santos AR, Pinto AC, Barbosa E, Aburjaile F, Ali A, Diniz CA, Hassan SS, Fiaux K, Guimarães LC....Corynebacterium pseudotuberculosis is the causative agent of several veterinary diseases in a broad range of economically important hosts, which can vary from caseous lymphadenitis in sheep and goats (biovar ovis) to ulcerative lymphangitis in cattle and horses (biovar equi). Existing vaccines against C. pseudotuberculosis are mainly intended for small ruminants and, even in these hosts, they still present remarkable limitations. In this study, we present the complete genome sequence of C. pseudotuberculosis biovar equi strain 258, isolated from a horse with ulcerative lymphangitis. The genome...
Meng Q, Lin Y, Ma J, Ma Y, Zhao L, Li S, Yang K, Zhou J, Shen R, Zhang X, Shao Y.Data from successful attenuated lentiviral vaccine studies indicate that fully mature Env-specific antibodies characterized by high titer, high avidity, and the predominant recognition of conformational epitopes are associated with protective efficacy. Although vaccination with a DNA prime/recombinant vaccinia-vectored vaccine boost strategy has been found to be effective in some trials with non-human primate/simian/human immunodeficiency virus (SHIV) models, it remains unclear whether this vaccination strategy could elicit mature equine infectious anemia virus (EIAV) Env-specific antibodies, ...
Verwoerd DW.In the early colonial history of South Africa, horses played an important role, both in general transportation and in military operations. Frequent epidemics of African horsesickness (AHS) in the 18th century therefore severely affected the economy. The first scientific research on the disease was carried out by Alexander Edington (1892), the first government bacteriologist of the Cape Colony, who resolved the existing confusion that reigned and established its identity as a separate disease. Bluetongue (BT) was described for the first time by Duncan Hutcheon in 1880, although it was probably ...
Libardoni F, Vielmo A, Farias L, Matter LB, Pötter L, Spilki FR, de Vargas AC.Strangles is the main upper respiratory tract disease of horses. There are currently no studies on the changes in alleles of the M protein gene (seM) in Brazilian isolates of Streptococcus equi ssp. equi (S. equi). This study aimed to analyze and differentiate molecularly S. equi isolates from equine clinical specimens from southern Brazil, between 1994 and 2010. seM alleles were analyzed in 47 isolates of S. equi obtained from clinical cases of strangles (15 Thoroughbred horses, 29 Crioulo breed horses and three Brasileiro de Hipismo--BH). seM alleles characterization was performed by compari...
Mahalingam S, Herrero LJ, Playford EG, Spann K, Herring B, Rolph MS, Middleton D, McCall B, Field H, Wang LF.Hendra virus, first identified in 1994 in Queensland, is an emerging zoonotic pathogen gaining importance in Australia because a growing number of infections are reported in horses and people. The virus, a member of the family Paramyxoviridae (genus Henipavirus), is transmitted to horses by pteropid bats (fruit bats or flying foxes), with human infection a result of direct contact with infected horses. Case-fatality rate is high in both horses and people, and so far, more than 60 horses and four people have died from Hendra virus infection in Australia. Human infection is characterised by an a...
Rodrigues MA, Figueiredo L, Padrela L, Cadete A, Tiago J, Matos HA, Gomes de Azevedo E, Florindo HF, Gonçalves LM, Almeida AJ.Strangles is an extremely contagious and sometimes deadly disease of the Equidae. The development of an effective vaccine should constitute an important asset to eradicate this worldwide infectious disease. In this work, we address the development of a mucosal vaccine by using a Supercritical Enhanced Atomization (SEA) spray-drying technique. Aqueous solutions containing the Streptococcus equi extracts and chitosan were converted into nanospheres with no use of organic solvents. The immune response in a mouse model showed that the nanospheres induced a well-balanced Th1 and Th2 response charac...
Witkowski L, Kaba J, Rzewuska M, Nowicki M, Szaluś-Jordanow O, Kita J.Rhodococcus equi infection occurs worldwide and is one of the major causes of losing foals in the first six months of life. The application of serological tests in the diagnostics of rhodococcosis is limited, however they play a crucial role in immunological studies. The objective of this study was to develop and standardize ELISA test for the determination of the level of antibodies against Rhodococcus equi in equine serum and colostrum.Bacterial cell lysate was used as antigen. The test was standardized on 175 sera obtained from adult horses kept on rhodococcosis-free and endemic farms. Posi...
Sponseller BA, Clark SK, Friedrich RA.Determining mechanisms of viral escape to particular epitopes recognized by virus-neutralizing antibody can facilitate characterization of host-neutralizing antibody responses as type- versus group-specific, and provides necessary information for vaccine development. Our study reveals that a single N-glycan located in the 5' region of the Wyoming wild-type equine infectious anemia virus (EIAV) principal neutralizing domain (PND) accounts for the differences in neutralization phenotype observed between PND variants, while variations in charged amino acids within the PND do not appear to play a ...
Zhang J, Go YY, Huang CM, Meade BJ, Lu Z, Snijder EJ, Timoney PJ, Balasuriya UB.A stable full-length cDNA clone of the modified live virus (MLV) vaccine strain of equine arteritis virus (EAV) was developed. RNA transcripts generated from this plasmid (pEAVrMLV) were infectious upon transfection into mammalian cells, and the resultant recombinant virus (rMLV) had 100% nucleotide identity to the parental MLV vaccine strain of EAV. A single silent nucleotide substitution was introduced into the nucleocapsid gene (pEAVrMLVB), enabling the cloned vaccine virus (rMLVB) to be distinguished from parental MLV vaccine as well as other field and laboratory strains of EAV by using an...
El Garch H, Crafford JE, Amouyal P, Durand PY, Edlund Toulemonde C, Lemaitre L, Cozette V, Guthrie A, Minke JM.A recombinant canarypox virus vectored vaccine co-expressing synthetic genes encoding outer capsid proteins, VP2 and VP5, of African horse sickness virus (AHSV) serotype 4 (ALVAC(®)-AHSV4) has been demonstrated to fully protect horses against homologous challenge with virulent field virus. Guthrie et al. (2009) detected weak and variable titres of neutralizing antibody (ranging from <10 to 40) 8 weeks after vaccination leading us to hypothesize that there could be a participation of cell mediated immunity (CMI) in protection against AHSV4. The present study aimed at characterizing the CMI ind...
Lunney JK, Kai C, Inumaru S, Onodera T.This special issue of Veterinary Immunology and Immunopathology summarizes the Proceedings of the 9th International Veterinary Immunology Symposium (9th IVIS) held August 2010, in Tokyo, Japan. Over 340 delegates from 30 countries discussed research progress analyzing the immune systems of numerous food animals and wildlife, probing basic immunity and the influence of stress, genetics, nutrition, endocrinology and reproduction. Major presentations addressed defense against pathogens and alternative control and prevention strategies including vaccines, adjuvants and novel biotherapeutics. A spe...
Manole V, Laurinmäki P, Van Wyngaardt W, Potgieter CA, Wright IM, Venter GJ, van Dijk AA, Sewell BT, Butcher SJ.African horsesickness (AHS) is a devastating disease of horses. The disease is caused by the double-stranded RNA-containing African horsesickness virus (AHSV). Using electron cryomicroscopy and three-dimensional image reconstruction, we determined the architecture of an AHSV serotype 4 (AHSV-4) reference strain. The structure revealed triple-layered AHS virions enclosing the segmented genome and transcriptase complex. The innermost protein layer contains 120 copies of VP3, with the viral polymerase, capping enzyme, and helicase attached to the inner surface of the VP3 layer on the 5-fold axis,...
Li D, Mattoo P, Keller JE.Hyperimmune monovalent antitoxins to botulinum neurotoxin serotypes A and B have been produced by immunizing horses with newly developed formalin toxoids. After primary immunization, horses developed acceptable prophylactic antibody titers (1-5 IU/mL). Three horses received additional toxoid booster injections to induce hyperimmune antibody titers with antitoxin-A and antitoxin-B titers reaching peaks of approximately 2000 IU/mL and 150-625 IU/mL, respectively. Titers were quantified throughout the process by antigen-capture ELISA and by in-vivo neutralization. ELISA titers and neutralization ...
Pusterla N, Vannucci FA, Mapes SM, Nogradi N, Collier JR, Hill JA, Difrancesco M, White AM, Akana NK, Simonek G, Gebhart CJ.To determine the efficacy of an avirulent Lawsonia intracellularis vaccine in preventing proliferative enteropathy in weanling foals. Methods: 12 healthy weanling foals. Methods: Foals were randomly assigned to a vaccinated, nonvaccinated, or control group. Vaccinated foals received an avirulent porcine L intracellularis frozen-thawed vaccine intrarectally 60 and 30 days prior to experimental challenge. On day 1, vaccinated and nonvaccinated foals were challenged via nasogastric intubation with a virulent heterologous isolate of L intracellularis. Control foals were not challenged. Clinical ob...
Tonkin DR, Whitmore A, Johnston RE, Barro M.Replicon particles derived from Venezuelan equine encephalitis virus (VEE) are infectious non-propagating particles which act as a safe and potent systemic, mucosal, and cellular adjuvant when delivered with antigen. VEE and VEE replicon particles (VRP) can target multiple cell types including dendritic cells (DCs). The role of these cell types in VRP adjuvant activity has not been previously evaluated, and for these studies we focused on the contribution of DCs to the response to VRP. By analysis of VRP targeting in the draining lymph node, we found that VRP induced rapid recruitment of TNF-s...
Ronchi GF, Ulisse S, Rossi E, Franchi P, Armillotta G, Capista S, Peccio A, Di Ventura M, Pini A.Monovalent, inactivated and adjuvanted vaccines against African horse sickness, prepared with serotypes 5 and 9, were tested on guinea-pigs to select the formulation that offered the greatest immunity. The final formulation of the vaccines took into account the immune response in the guinea-pig and the inflammatory properties of two types of adjuvant previously tested on target animals. A pilot study was subsequently conducted on horses using a vaccine prepared with serotype 9. The vaccine stimulated neutralising antibodies from the first administration and, after the booster dose, 28 days lat...
Ault A, Zajac AM, Kong WP, Gorres JP, Royals M, Wei CJ, Bao S, Yang ZY, Reedy SE, Sturgill TL, Page AE, Donofrio-Newman J, Adams AA, Balasuriya UB....Equine influenza A (H3N8) virus infection is a leading cause of respiratory disease in horses, resulting in widespread morbidity and economic losses. As with influenza in other species, equine influenza strains continuously mutate, often requiring the development of new vaccines. Current inactivated (killed) vaccines, while efficacious, only offer limited protection against diverse subtypes and require frequent boosts. Research into new vaccine technologies, including gene-based vaccines, aims to increase the neutralization potency, breadth, and duration of protective immunity. Here, we demons...
Pretorius A, Van Kleef M, Van Wyngaardt W, Heath J.African horsesickness (AHS) is an infectious but noncontagious viral disease affecting all species of Equidae. The recall immune response of AHSV naïve horses immunised with an attenuated African horsesickness virus serotype 4 (AHSV4) was characterised using immune assays including ELISPOT, real-time PCR (qPCR) and flow cytometry. The recall immune response detected in PBMC isolated from three inoculated horses showed an upregulation of circulating B lymphocytes that correlated with elevated IL-4 mRNA expression indicative of humoral immunity, but reduced frequency of CD4⁺ cells. In additio...
Matthijnssens J, Miño S, Papp H, Potgieter C, Novo L, Heylen E, Zeller M, Garaicoechea L, Badaracco A, Lengyel G, Kisfali P, Cullinane A, Collins PJ....In this study, the complete genome sequences of seven equine group A rotavirus (RVA) strains (RVA/Horse-tc/GBR/L338/1991/G13P[18], RVA/Horse-wt/IRL/03V04954/2003/G3P[12] and RVA/Horse-wt/IRL/04V2024/2004/G14P[12] from Europe; RVA/Horse-wt/ARG/E30/1993/G3P[12], RVA/Horse-wt/ARG/E403/2006/G14P[12] and RVA/Horse-wt/ARG/E4040/2008/G14P[12] from Argentina; and RVA/Horse-wt/ZAF/EqRV-SA1/2006/G14P[12] from South Africa) were determined. Multiple novel genotypes were identified and genotype numbers were assigned by the Rotavirus Classification Working Group: R9 (VP1), C9 (VP2), N9 (NSP2), T12 (NSP3), ...
Paillot R, Prowse L.The humoral immune response induced by ISCOM-matrix (Immuno Stimulating COMplex-Matrix)-adjuvanted equine influenza virus (EIV) vaccine is well documented in horses. ISCOM-matrix adjuvanted vaccines against human influenza are strong inducers of cell-mediated immunity (CMI), including T cell proliferation and virus-specific cytotoxic T cell. In the horse, the CMI response to equine influenza vaccination is less well characterised. An ISCOM-based vaccine has been shown to induce interferon gamma (IFN-γ) synthesis, a CMI marker, in the horse, but this has not been shown for the ISCOM-matrix vac...
Goodyear A, Troyer R, Bielefeldt-Ohmann H, Dow S.The Gram-negative bacterium Burkholderia mallei causes rapidly fatal illness in equines and humans when contracted by inhalation and also has the potential to be used as a bioweapon. However, little is known regarding the early innate immune responses and signaling mechanisms required to generate protection from pneumonic B. mallei infection. We showed previously that monocyte chemoattractant protein 1 (MCP-1) was a critical chemokine required for protection from pneumonic B. mallei infection. We have now extended those studies to identify key Toll-like receptor (TLR) signaling pathways, effec...
Cauchard S, Bermúdez-Humarán LG, Blugeon S, Laugier C, Langella P, Cauchard J.Rhodococcus equi causes severe pneumonia in foals and has recently gained attention as a significant opportunistic pathogen in immunocompromised humans. However, no effective vaccine to prevent rhodococcosis is currently available. In this study, we have engineered the food-grade bacterium Lactococcus lactis to secrete the virulence-associated protein A from R. equi (LL-VapA). The immunogenic potential of LL-VapA strain was then evaluated after either intragastric or intranasal immunization in mice either alone or in combination with LL-Lep, a recombinant strain of L. lactis secreting biologic...
Gildea S, Quinlivan M, Arkins S, Cullinane A.Antigenic and genetic drift of equine influenza (EI) virus is monitored annually by the Expert Surveillance Panel (ESP), which make recommendations on the need to update vaccines. Surveillance programmes are essential for this process to operate effectively and to decrease the risk of disease spread through the international movement of subclinically infected vaccinated horses. Not only is surveillance necessary to inform vaccine companies which strains are in circulation, but it serves as an early warning system for horse owners, trainers and veterinary clinicians, facilitating the implementa...
Lewis NS, Daly JM, Russell CA, Horton DL, Skepner E, Bryant NA, Burke DF, Rash AS, Wood JL, Chambers TM, Fouchier RA, Mumford JA, Elton DM, Smith DJ.Equine influenza virus is a major respiratory pathogen in horses, and outbreaks of disease often lead to substantial disruption to and economic losses for equestrian industries. The hemagglutinin (HA) protein is of key importance in the control of equine influenza because HA is the primary target of the protective immune response and the main component of currently licensed influenza vaccines. However, the influenza virus HA protein changes over time, a process called antigenic drift, and vaccine strains must be updated to remain effective. Antigenic drift is assessed primarily by the hemagglu...
van Rijn PA, Maris-Veldhuis MA, Grobler M, Wright IM, Erasmus BJ, Maartens LH, Potgieter CA.African horse sickness virus (AHSV) is a virus species in the genus Orbivirus of the family Reoviridae causing African Horse Sickness (AHS) in equids with a mortality of about 95% in naïve horses. AHS causes serious losses in developing countries where horses play a central role in draft power and transportation. There are nine AHSV serotypes inducing no or low cross-neutralizing antibodies. AHSV is spread by biting Culicoides midges. AHS is endemic in sub-Saharan Africa, and a serious threat outside Africa, since Culicoides species in moderate climate conditions are spreading the closely rel...
Kirkpatrick JF, Turner JW, Liu IK, Fayrer-Hosken R, Rutberg AT.Non-lethal management methods are required for wild equids that are protected by law and for deer inhabiting areas where lethal controls are not legal or safe. Single or multiple inoculations of porcine zona pellucida (PZP) vaccine have been delivered to wild horses and deer by means of darts. Contraceptive efficacy in horses after two inoculations ranged from 90% to 100%, and after a single inoculation ranged from 19% to 28%. Mares given a controlled-release form of the vaccine had foaling rates ranging from 7% to 20%. No detectable changes in social organization or behaviours among treated h...
Gauci PJ, Wu JQ, Rayner GA, Barabé ND, Nagata LP, Proll DF.DNA vaccines encoding different portions of the structural proteins of western equine encephalitis virus were tested for the efficacy of their protection in a 100% lethal mouse model of the virus. The 6K-E1 structural protein encoded by the DNA vaccine conferred complete protection against challenge with the homologous strain and limited protection against challenge with a heterologous strain.
Esparza J.Mystery surrounds the extent to which horsepox virus may have contributed to the vaccinia virus used to eradicate smallpox. With few documented cases of horsepox in recent years it may never be solved, says José Esparza, who seeks to raise awareness of the potential historical and scientific importance of identifying new cases.
Cauchard S, Bertrand F, Barrier-Battut I, Jacquet S, Laurentie M, Barbey C, Laugier C, Deville S, Cauchard J.Rhodococcus equi is the most common infectious cause of mortality in foals between 1 and 6 months of age. Because of an increase in the number of antibiotic-resistant strains, the optimization of a prophylactic strategy is a key factor in the comprehensive management of R. equi pneumonia. The objectives of this study were to assess the safety and immunogenicity of R. equi-secreted proteins (ReSP) co-administered with either the nanoparticular adjuvant Montanide™ IMS 3012 VG, or a new polymeric adjuvant Montanide™ PET GEL A, and to further investigate the most immunogenic proteins for subse...
Barbey C, Budin-Verneuil A, Cauchard S, Hartke A, Laugier C, Pichereau V, Petry S.Rhodococcus equi is one of the most important causes of mortality in foals between 1 and 6 months of age. Although rare, infection also occurs in a variety of other mammals including humans, often following immunosuppression of various causes. Secreted proteins are known to mediate important pathogen-host interactions and consequently are favored candidates for vaccine development as they are the most easily accessible microbial antigens to the immune system. Here, we describe the results of a proteomic analysis based on SDS-PAGE, immunoblot and mass spectrometry, which was carried out aiming ...
Blanco-Lobo P, Rodriguez L, Reedy S, Oladunni FS, Nogales A, Murcia PR, Chambers TM, Martinez-Sobrido L.Vaccination remains the most effective approach for preventing and controlling equine influenza virus (EIV) in horses. However, the ongoing evolution of EIV has increased the genetic and antigenic differences between currently available vaccines and circulating strains, resulting in suboptimal vaccine efficacy. As recommended by the World Organization for Animal Health (OIE), the inclusion of representative strains from clade 1 and clade 2 Florida sublineages of EIV in vaccines may maximize the protection against presently circulating viral strains. In this study, we used reverse genetics tech...
Hoffman AM, Staempfli HR, Prescott JF, Viel L.A double-blind randomized clinical trial was undertaken to determine the value of parenterally administered Streptococcus equi M-protein vaccine in foals during an epizootic of strangles. Weaned mixed-breed foals (n = 664) housed on 2 adjacent feed-lots (A and B) arrived over a 5-day period, 2 weeks before primary vaccination. Foals in lot B (n = 114) were randomly administered vaccine (n = 59) or saline solution (placebo; n = 55) on 3 occasions at biweekly intervals. Foals in lot A (n = 450) were given 1 dose of vaccine (n = 225) or placebo. The following clinical observations were scored bli...
Ons E, Van Brussel L, Lane S, King V, Cullinane A, Kenna R, Lyons P, Hammond TA, Salt J, Raue R.The efficacy of Zylexis®, an immunomodulator in horses based on inactivated Parapoxvirus ovis (iPPVO), was assessed using an equine herpesvirus type 1 (EHV-1) challenge model in the presence of a natural infection with Streptococcus equi equi (S. equi). Eleven horses were treated with iPPVO and twelve were kept as controls. Six horses were challenged with EHV-1 and commingled with the horses on study. Animals were dosed on Days -2, 0 (just before commingling) and Day 7. On Day 11 significantly less nasal discharge, enlarged lymph nodes, EHV-1 shedding and lower rectal temperatures were observ...
Meng Q, Lin Y, Ma J, Ma Y, Zhao L, Li S, Liang H, Zhou J, Shen R, Zhang X, Shao Y.The attenuated Chinese equine infectious anemia virus (EIAV) vaccine has successfully protected millions of equine animals from EIA disease in China. In this pilot study, to determine whether this attenuated vaccine can induce broadly neutralizing antibodies, we immunized four horses with the attenuated Chinese vaccine strain EIAVFDDV and then observed the evolution of neutralizing antibodies against different EIAV strains. During the vaccination phase, all vaccinees rapidly developed high levels of neutralizing antibodies against the homologous vaccine strain (pLGFD3V), and 3 out of 4 horses ...
van Rijn PA, Maris-Veldhuis MA, Boonstra J, van Gennip RGP.African Horse Sickness Virus (AHSV) (Orbivirus genus, Reoviridae family) causes high mortality in naïve domestic horses with enormous economic and socio-emotional impact. There are nine AHSV serotypes showing limited cross neutralization. AHSV is transmitted by competent species of Culicoides biting midges. AHS is a serious threat beyond the African continent as endemic Culicoides species in moderate climates transmit the closely related prototype bluetongue virus. There is a desperate need for safe and efficacious vaccines, while DIVA (Differentiating Infected from Vaccinated) vaccines would...
Fehér O, Bakonyi T, Barna M, Nagy A, Takács M, Szenci O, Joó K, Sárdi S, Korbacska-Kutasi O.In the last decade in Hungary and the neighbouring countries, West Nile Neuroinvasive Disease (WNND) has been caused in dramatically increasing numbers by lineage 2 West Nile Virus (WNV) strains both in horses and in humans. The disease in this geographical region is seasonal, so vaccination of horses should be carefully scheduled to maintain the highest antibody titres during outbreak periods. The objective of this study was to characterise the serum neutralising (SN) antibody titres against a lineage 2 WNV strain in response to vaccination with an inactivated lineage 1 vaccine (Equip® WNV)....
Matthijnssens J, Ons E, De Coster S, Conceição-Neto N, Gryspeerdt A, Van Ranst M, Raue R.Equine group A rotavirus (RVAs) mainly cause disease in foals under the age of 3 months. Only sporadic data are available on the circulation of RVAs in equine populations in Europe. In this study, 65 diarrheic samples from foals under 4 months of age were collected in Belgium (n=32), Germany (n=17), Slovenia (n=5), Sweden (n=4), Hungary (n=3), Italy (n=2), France (n=1) and The Netherlands (n=1). Forty percent of these samples (n=26) were found to be RVA positive by a quantitative RT-PCR assay. The viral load in 11 of these samples was sufficiently high to be (partially) genotyped. G3, G14 and ...
Mumford JA, Wood JM, Folkers C, Schild GC.Thirty-one ponies immunized with inactivated virus vaccine containing A/equine/Miami/63 (H3N8) virus and six seronegative ponies were experimentally challenged with the homologous virus strain. All 6 unvaccinated ponies and 11 out of 31 vaccinated ponies became infected. A clear relationship between pre-challenge antibody, measured by single radial haemolysis (SRH), and protection was demonstrated as judged by virus excretion, febrile responses and antibody responses. Those ponies with SRH antibody levels greater than 74 mm2 were completely protected against challenge infection by the intranas...
Entenfellner J, Gahan J, Garvey M, Walsh C, Venner M, Cullinane A.The international governing body of equestrian sports requires that horses be vaccinated against equine influenza within 6 months and 21 days of competing. The aim of this study was to compare the antibody response of young sport horses to six-monthly booster vaccination with equine influenza vaccines of different formulations. An inactivated vaccine was allocated to 35 horses and subunit and recombinant vaccines were allocated to 34 horses each. After vaccination, all horses were monitored for evidence of adverse reactions. Whole blood samples were collected at the time of vaccination and on ...
Paillot R, Kydd JH, MacRae S, Minke JM, Hannant D, Daly JM.Equine influenza virus (EIV) is a leading cause of respiratory disease in horses. Equine influenza infection induces a long-term immunity to re-infection. Recent strategies of vaccination aim to mimic this immunity by stimulating both antibody and cellular immune responses. Cell-mediated immunity (CMI) to influenza is well defined in man, but little has been done to characterise the responses in the horse. Additionally, the development of reliable assays for the measurement of equine CMI has lagged behind serological methods and vaccine development. In this study, two methods of measuring EIV-...
Tan R, Hodge A, Klein R, Edwards N, Huang JA, Middleton D, Watts SP.To determine the antibody responses to a commercial Hendra virus vaccine (Equivac® HeV) in a field environment. Methods: A group of 61 horses received a primary vaccination course comprising two doses administered 3-6 weeks apart (V1, V2) and a 3rd dose (V3) given 6 months after the second. This was followed by booster vaccinations at 12 monthly intervals (V4, V5). Antibody titres were assessed using a virus-neutralisation test. Results: Neutralising antibodies against HeV were not detected prior to vaccination. Antibodies were detected in 54/57 horses at 3 weeks after V1 and 51/51 had ...
Heldens JG, Kersten AJ, Weststrate MW, van den Hoven R.An adjuvanted vaccine containing inactivated equine influenza, herpesvirus antigens, and tetanus toxoid was administered to young seronegative foals of 8 months of age by deep intramuscular injection in the neck (Group A). The first two vaccinations were given 4 weeks apart. The third was administered 6 months later. Another group of foals (Group B) was vaccinated according to the same scheme at the same time with monovalent equine herpes virus (EHV) vaccine (EHV1.4) vaccine. Antibody responses to the equine influenza (single radial haemolysis; SRH) and tetanus (ToBi ELISA) components of the v...
Robinson C, Frykberg L, Flock M, Guss B, Waller AS, Flock JI.The host-restricted pathogen Streptococcus equi causes strangles in the horse, which is characterised by abscessation of the lymph nodes of the head and neck. The disease is endemic throughout the world causing considerable welfare and economic cost to the horse industry. Here we report the results of three studies where ponies were vaccinated with combinations of recombinant fusion proteins to optimise vaccine production and the level of protection conferred. Optimal protection was conferred by a prototype multicomponent subunit vaccine, Strangvac 4, which contained eight proteins CNE, SclC, ...
Harris SP, Hines MT, Mealey RH, Alperin DC, Hines SA.Rhodococcus equi is an important respiratory pathogen of young foals for which a vaccine has long been sought. Two major impediments to effective vaccination are the functionally immature type I immune responses of neonatal foals and early exposure to the bacterium via the environment. Despite these obstacles, it appears that under specific circumstances foals can develop a protective immune response. In this study we investigated the protective mechanisms behind oral inoculation of foals with virulent R. equi bacteria. Two foals receiving an oral inoculum demonstrated accelerated development ...
Chang Y, Novosol V, McDonough SP, Chang CF, Jacobson RH, Divers T, Quimby FW, Shin S, Lein DH.Eight 1-year-old ponies were vaccinated with recombinant OspA (ospA gene derived from B. burgdorferi B31) with adjuvant (aluminium hydroxide). Four ponies were used as non-vaccinated controls with adjuvant. One hundred and twelve days after the first vaccination, the vaccinated and non-vaccinated ponies were challenged by exposure to B. burgdorferi-infected adults tick (Ixodes scapularis) collected from Westchester County, New York (tick infection rate >/=60%). Protection from infection was evaluated by culture for B. burgdorferi from three monthly skin biopsies taken near the site of tick bit...
Ma J, Jiang C, Lin Y, Wang X, Zhao L, Xiang W, Shao Y, Shen R, Kong X, Zhou J.To study the in vivo evolution of the attenuated Chinese equine infectious anemia virus (EIAV) vaccine, viral gp90 gene variation and virus replication in immunosuppressed hosts were investigated. The results showed that after vaccination, the gp90 gene followed an evolutionary trend of declining diversity. The trend coincided with the maturation of immunity to EIAV, and eventually, the gp90 gene became highly homologous. The sequences of these predominant quasispecies were consistently detected up to 18 months after vaccination. Furthermore, after transient immune suppression with dexamethaso...
Craigo JK, Barnes S, Zhang B, Cook SJ, Howe L, Issel CJ, Montelaro RC.Equine infectious anemia virus (EIAV), a lentivirus that infects horses, has been utilized as an animal model for the study of HIV. Furthermore, the disease associated with the equine lentivirus poses a significant challenge to veterinary medicine around the world. As with all lentiviruses, EIAV has been shown to have a high propensity for genomic sequence and antigenic variation, especially in its envelope (Env) proteins. Recent studies have demonstrated Env variation to be a major determinant of vaccine efficacy, emphasizing the importance of defining natural variation among field isolates o...
Go YY, Snijder EJ, Timoney PJ, Balasuriya UB.Equine arteritis virus (EAV) replicase consists of two polyproteins (pp1a and pp1ab) that are encoded by open reading frames (ORFs) 1a and 1b of the viral genome. These two replicase polyproteins are posttranslationally processed by three ORF 1a-encoded proteinases to yield at least 13 nonstructural proteins (nsp1 to nsp12, including nsp7α and 7β). These nsps are expressed in EAV-infected cells, but the equine immune response they induce has not been studied. Therefore, the primary purpose of this study was to evaluate the humoral immune response of horses to each of the nsps following EAV i...
Bell CW, Boyle DB, Whalley JM.Transcript mapping of the equine herpesvirus 1 (EHV-1) glycoprotein B (gB) gene homologue by Northern blot, S1 nuclease and primer extension analyses indicated that two overlapping transcripts of 3.4 and 4.6 kb originated from the same strand and were transcribed from left to right between coordinates 0.40 and 0.43 of the EHV-1 genome. The 3.4 kb transcript encoded EHV-1 gB and the 5' RNA terminus was located approximately 30 bases downstream from a probable TATA element. The coding region of the gB gene homologue was reconstructed from two subclones using oligonucleotide mutagenesis and inser...
Sundquist B, Lövgren K, Morein B.A monovalent experimental ISCOM vaccine has been prepared with the envelope glycoproteins haemagglutinin and neuraminidase of the equine virus strain A/Solvalla/79 (H3N8). In vaccination trials on BALB/c mice the ISCOM vaccine induced more than ten times higher serum antibody titres measured in ELISA than a corresponding experimental micelle vaccine. Similarly, in guinea-pigs the ISCOMs induced about tenfold higher haemagglutination inhibition (HI) and neuraminidase inhibition (NI) titres than a micelle vaccine or a conventional killed influenza whole virus vaccine. Horses vaccinated with a di...
Swayze RD, Bhogal HS, Barabé ND, McLaws LJ, Wu JQ.Western equine encephalitis virus (WEEV) is a mosquito-borne RNA virus which causes lethal infection in humans and equines. There are no commercial vaccines or anti-WEEV drugs available for humans. We used replication-defective, human adenovirus serotype-5 (HAd5) as a delivery vector for developing WEEV vaccine. Our previous study found delivery of both E1 and E2 envelope proteins of WEEV by HAd5 vector offers complete protection against lethal challenge of WEEV. In this paper, we constructed a HAd5-vectored E1 vaccine, Ad5-E1. Mice given single-dose vaccination of Ad5-E1 were completely prote...
Horohov DW, Breathnach CC, Sturgill TL, Rashid C, Stiltner JL, Strong D, Nieman N, Holland RE.While immune modulators are used routinely in equine medicine, their mechanism of action is not always known. Objective: To determine the effect of a commercial preparation of inactivated parapoxvirus ovis (Orf virus; PPVO) on cytokine gene expression by equine peripheral blood mononuclear cells (PBMC) both in vitro and in vivo. Methods: PBMC were prepared from 6 mixed-breed yearlings and cultured in vitro with PPVO with or without Concanavalin A (Con A) for 24 h. Effects on the expression of IFNalpha, IFNbeta IFNgamma, TNFalpha and IL-18 were analysed by real time quantitative PCR (RT-PCR). I...
Barber MR, Fayrer-Hosken RA.Ecological and conservation programs in ecosystems around the world have experienced varied success in population management. One of the greatest problems is that human expansion has led to the shrinking of wildlife habitat and, as a result, the overpopulation of many different species has occurred. The pressures exerted by the increased number of animals has caused environmental damage. The humane and practical control of these populations has solicited the scientific community to arrive at a safe, effective, and cost-efficient means of population control. Immunocontraception using zona pellu...
